High-frequency signaling system



Jan. 8, 1929. 1,698,706

' I. F. BYRNES HIGH FREQUENCY SIGNALING SYSTEM Filed Dec. 2'7, 1926 22 /4 [ll fav 3 Z ipj J2 g l n 6 24 L l J H Z6} 2 x1- Z0 l5 2 0 a W T /J ll 'A'l A'A I J a A I V Inventor: InvLng F. Bgnnes,

' HLS Attonneg.

vPatented Jan. 8, 1929.

HIGH-FREQUENCY SIGNALING SYSTEM.

GENERAL E EcrRIc V Application'filed December 27,1926, Serial No. 157,033.

, My invention relates to the controlling means. for high frequency signaling systems and particularly to the transmitters ofsuch systems which employ in addition to an'oscillation generator, a power amplifier for the oscillations produced by the oscillation generator and it has for its purpose to provide a means for simultaneously controlling the operation ofboth the oscillation generator andthe amplifier.

It has heretofore been proposed. to maintain the circuits of the amplifier in one con- 'dition and vto effect the signalsby means of a key shunted by a condenser in thegrid circuit of the oscillator. This arrangement has the disadvantage that aseparate source of grid potential must be provided for the power I It has also beenproposed to maintain the master oscillator in continuous operation and toefl'ect the signals by means of a key shunted by a suitable condenser in the grid circuit of the amplifier. This means has the disadvantage that when the key is open alternating current from the oscillator will-be impressed upon the input circuit oft-he amplifier.

- I propose to overcome the alcove disadvantages by simultaneously controlling the grid voltages of both theamplifier and the oscillator by the same means.

The novel features which I believe to be- .characteristic. of my invention are set forth I with particularity in the appended claims.

My invention itself howevenboth asto its 1 organization and method of operation willbest be understood by reference to the follow 7 ing description takeninconnection with the accompanying drawing in which I have. "shown diagrammatically one way whereby my invention may be carried into effect.

In the single figure of the drawmg, 1- represents an oscillator. 2 and 3 are amplifiers wh1ch in this particular. embodnnent aregconnected' in parallel and which receive their 1nput supply from the oscillator 1 and supply their output voltages to the transformer 4 1 i of the antenna system'5. The circuit of the oscillator 1 may be that ofany of the usual types of oscillators. The cathodes of the amplifiers 2 and of the oscillator 1 are energized through conductorsfiand 7 and conductors 8 and 9 from a secondary wind-, ing .of'the filament transformer 10, the pri mary winding of which may be excited from any sultable source of alternating current rescues 1 earenrorrica IRVING F. BYRNES, OF SCHENECTADY, N YORK, ASSIGNOR TO COMPANY, A CORPORATION OF NEW YORK;

potential. While I have shown alternating current used as a cathode supply in this partlCUliLP-RPPllOfltlOll of my invention, it is to be understood thatdirect v used as well. i The anodes of the amplifiers 2 and 3 are connected through a conductor 11, primary winding of transformer4, switch conductor 13' to the positive sideof the h gh. voltage source 14. (Likewise, the anode of theoscillator 1 is supplied With a high potentialthrough the conductor'15, choke C011 16, and conductor 17. The choke coil 16 is the usual high-frequency choke to. prevent the passage of radio frequencies into the direct current source 14. The negative side of the high voltage source 14 ispreferably connectedto ground an'dalso to. the mid-tap of the secondary winding of the cathode transcurrent may be.

former 10 through conductors 18 and 19. l The through a blocking condenser 24, and having an intermediate point 25 connected to the cathode through the'conductor 26 and conductor 19; The output voltage of the oscil- 1am is obtained from the condenser 27 which comprisesa part of the oscillatory. cir-' A cuit 20 and one plate; of which is maintained at the potential ofthe cathode through the circuit already described. The other plate is connected. through a circuit comprising the coupling condenser 28; resistance .29, conduc- -tor 30 conductor 31 and conductors 32 to the grids of the amplifier tubes 2and 3. This circuit is also connected through the inductance'coil 33, resistance 34, control condenser 35, resistance 36, conductor 37 to the negative side of the source of potential 14. i The. grid of the oscillatoris connected through the eonductor 22, resistance 38', conductor 40,'conductor 41 to the control condenser 35-. It is thus seen that the grid or control circuits, of the amplifier tubes and also of the master oscillator are both connectedto the sameside v .of the control condenser 35. This condenser together with its resistance j 36' are shunted by means of the control key or chopper 39. The purpose of the resistance 36 is 'to con- 'trol the rateof charge and discharge ofcondenser 35. V Y The operation of my circuit is as follows:

Assuming that the key 39 is closed, the grids of all the tubes will then have impressed thereon the normal operating potential. The circuit of the grid of the oscillator tube 1 extends through conductor 22, .resistance38,

conductor 40, key 39, conductor 37 to the negative side of the sourcel-it. The circuit of the grids of the amplifiers 2 and 3 will extend through the conductors 32, conductor 31, inductance33, resistance 34, conductor 41,

key 39,,and conductor37 to the negative side of the source 14.21%; will thus be seen that the control condenser 35 and its associated resistance 36 are short circuited and are therefore ineffective. Oscillatorycurrent will be excited in the circuit by the oscillator tube 1 and the alternating current potential, which will appear across the condenser 27, will be impressed upon the grids of thepower amplifiers through the circuit including the coupling condenser 28, resistance 29', conductor 30, conductor 31 and conductors 32. These oscillations will be amplified by the amplifiers, 2 and 3 and transmitted to the antenna circuit. through the anode circuits of the power amplifiers in the usual way.

Assuming now that t is desired to interrupt the transmission in accordance with signals which are to be transmitted, the key 39 will be opened. This breaks the short circuit which previously existed aroundthe condenser-35 and resistance 36 through the key 39, conductor 10, and conductor 41. A high 1 negative charge will then build up on the condenser 35, causing a. strong negative potentia-l corresponding to the potential on'the condenser'35 to be impressed upon the grids of both the oscillator and the amplifier,

thereby interrupt-ingthe operation of both It is thus seen that I have provided a system in whichboth the operation of the oscillation generatoiyand also of the amplifiers is completely interrupted in accordance with r v the operation of thesingle key 39 and that this is brought about without the addition of any controlling meanspor negative bias for the amplifiers 2 and 3, as distinct from that of the oscillator.

- be apparent that my invention is not limited L While I have shown and described the preferred embodiment of my invention it will tothe particular embodiment shown but that many modifications in the circuit arrangemerits and instrumentalities employed in carrying out my invention may be made'without departing from the scope thereof as set forth in the appended claims. v

WVhat I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In a high frequency signaling system,

an oscillation generator, :1 high frequency amplifier connected to amplify the oscillations produced by said oscillation generator, a control circuit for said oscillation generator, a controlcircuit for said high frequency amplifier and a common-meanscomprising a single pair of contacts for controlling both of said control circu ts- 2. In a high frequency signaling system, i

an oscillation generator, ahigh frequency amplifier connected to amplify the oscilla tionsproduced by said oscillation generator,

a controlcircuit for said oscillation generator, a control circuit for said high frequency amplifier, said control circuits comprising direct current paths for said generator and amplifier, a common meansfor controllingboth of said control circuits, said means comprising a condenser connected inboth of. said control circuits and adapted when charged to prevent the operation of said oscillator and Y amplifier and a contact making key for short circuiting said condenser,

a vacuum plifier connected to amplify the oscillations 3. In a, high frequency signaling system, i

' tube oscillator, ,a, vacuum tube am-.

producedby said Vacuum tube oscillator, a

cathodecircuitfor said vacuunitube oscillator and for said vacuum" tube amplifier, a

control circuit for said vacuum tube oscillator, a control circuit for said vacuum tube amplifier, a condenser connected between said M cathode circuit and a'common point OII SH-Id control circuits and a 'keyconnected across said condenser the potential on both of saidcontrol circuits with respect: to said cathode circuit being determinedby said condenser I when said key is open; I q

4. In a high frequencysignaling system,

a vacuum tube oscillationgenerator,avacuum.

tube high frequency'amplifier, a cathode circuit for said oscillation generator andfor said high frequency amplifier, a control circuit for said oscillation generator, a control circuit for said high frequency amplifier, a condenser connected between said cathode circuit and a common pointon said control circuits'and a key connected acrosssaidcondenser the potential on both of" said control circuits with respect to said cathode circuit. being determined by; said condenser when said key is open. 1 ,7 g

In witness whereof, I have l'iereunto set my hand this 23d day of'December, 1926.

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